Figure 7.

RISC complexes formed on the 5′-strand of mivaRNAI are more stable than RISC assembled on the 3′-strand. (A) S15 cytoplasmic extracts prepared from Ad5 infected 293 cells were pre-incubated with 10 µM of a non-specific siRNA for 0, 10, 30, 60 or 120 min before RISC activity directed against the reverse VAI 5′ or reverse VAI 3′ target RNAs was measured. The cleavage ratio of target RNAs was quantitated by PhosphorImager scanning. The cleavage activity of the zero minute sample was arbitrarily set as 100%. (B) Target RNAs complementary to miR-18a, miR-93 and miR-106b were incubated in S15 extracts prepared from 293 cells as described in (A). RISC activity was quantitated by PhosphorImager scanning and the cleavage activity of the zero minute sample set as 100%.